Autonomous ventilation system

Abstract

An autonomous ventilation system includes a variable-speed exhaust fan, a controller, an exhaust hood, and a spillage sensor. The exhaust fan removes air contaminants from an area. The controller is coupled to the exhaust fan and adjusts the speed of the exhaust fan. The exhaust hood is coupled to the exhaust fan and directs air contaminants to the exhaust fan. The spillage sensor is coupled to the controller, detects changes in an environmental parameter in a spillage zone adjacent to the exhaust hood, and communicates information relating to detected changes in the environmental parameter to the controller. The controller adjusts the speed of the exhaust fan in response to information relating to detected changes in the environmental parameter.

What is claimed is: 
     
       1. An autonomous ventilation system comprising:
 a variable-speed exhaust fan operable to remove an air contaminant from an area; 
 a controller coupled to the variable-speed exhaust fan and operable to adjust the speed of the exhaust fan; 
 an exhaust hood coupled to the exhaust fan, the exhaust hood operable to direct the air contaminant to the exhaust fan; and 
 a spillage probe assembly adjacent to an edge of the exhaust hood, the spillage probe assembly including:
 an open housing that attaches the spillage probe assembly to the exhaust hood having a first side and a second opposite side attached to the exhaust hood and a third side connected to the first and second sides distal the exhaust hood, the open housing being constructed so as to allow air escaping the exhaust hood to pass through at least a portion thereof; 
 a spillage sensor arranged within a spillage zone, which is adjacent to the exhaust hood and at or above said edge of the exhaust hood, the spillage sensor being configured to detect a change in an environmental parameter in the spillage zone due to the air escaping the exhaust hood and to communicate information relating to detected changes in the environmental parameter to the controller; and 
 a sensor support extending between the first and second sides that couples the spillage sensor to the open housing, the sensor support being configured such that the spillage sensor can be slidably repositioned along the housing, 
 
 wherein the controller is further operable to adjust the speed of the fan in response to information relating to changes in the environmental parameter detected by the spillage sensor. 
 
     
     
       2. The system of  claim 1 , further comprising an ambient temperature sensor disposed in said area and remote from the exhaust hood, wherein the spillage sensor is a temperature sensor, the environmental parameter is a temperature in the spillage zone, and the controller is configured to control the exhaust fan speed responsively to a difference between the temperature detected by the spillage sensor and a temperature detected by the ambient temperature sensor. 
     
     
       3. The system of  claim 1 , wherein the spillage sensor is an air flow rate sensor arranged in the spillage zone to measure air flow rate in a vertical direction, and the environmental parameter is air flow rate in the vertical direction. 
     
     
       4. The system of  claim 1 , wherein the open housing includes a panel facing the exhaust hood and the spillage sensor is arranged between said panel and the exhaust hood. 
     
     
       5. The system of  claim 1 , further comprising a variable speed supply fan coupled to the controller and operable to deliver air to said area, wherein the controller is configured to control the supply fan responsively to the speed of the exhaust fan. 
     
     
       6. The system of  claim 1 , wherein said sensor support includes a tensioned cable, and the spillage sensor slides along the tensioned cable for repositioning. 
     
     
       7. The system of  claim 1 , wherein the spillage probe assembly further includes a second spillage sensor, and said sensor support suspends both of the spillage sensors from the open housing such that each spillage sensor can be slidably repositioned along the open housing independent of each other and such that each spillage sensor is isolated from the open housing. 
     
     
       8. The system of  claim 1 , wherein the spillage probe assembly further includes an over-ride unit coupled to the controller and configured to provide manual control of the speed of the exhaust fan. 
     
     
       9. A method of ventilating an area comprising:
 providing a controller coupled to a variable-speed exhaust fan, the variable-speed exhaust fan having an associated exhaust hood and being operable to remove an air contaminant from an area; 
 providing a spillage probe assembly adjacent to an edge of the exhaust hood, the spillage probe assembly including:
 an open housing that attaches the spillage probe assembly to the exhaust hood having a first side and a second opposite side attached to the exhaust hood and a third side connected to the first and second sides distal the exhaust hood, the open housing being constructed so as to allow air escaping the exhaust hood to pass through at least a portion thereof; 
 a spillage sensor arranged within a spillage zone, which is adjacent to the exhaust hood and at or above said edge of the exhaust hood, 
 the spillage sensor being coupled to the controller; and 
 a sensor support extending between the first and second sides that couples the spillage sensor to the open housing, the sensor support being configured such that the spillage sensor can be slidably repositioned along the housing; 
 sensing a change in an environmental parameter in the spillage zone due to the air escaping the exhaust hood using the spillage sensor; and 
 adjusting the speed of the variable-speed exhaust fan using the controller based on the environmental parameter change sensed by the spillage sensor in the spillage zone. 
 
 
     
     
       10. The method of  claim 9 , wherein: an ambient temperature sensor is provided in said area and remote from the exhaust hood, the spillage sensor is a temperature sensor, the environmental parameter is a temperature in the spillage zone, and said adjusting the exhaust fan speed includes controlling the exhaust fan speed responsively to a difference between the temperature detected by the spillage sensor and a temperature detected by the ambient temperature sensor. 
     
     
       11. The method of  claim 9 , wherein the spillage sensor is an air flow rate sensor arranged in the spillage zone to measure air flow rate in a vertical direction, and the environmental parameter is air flow rate in the vertical direction. 
     
     
       12. The method of  claim 9 , wherein the providing a spillage probe assembly includes positioning the third side of the open housing such that the spillage sensor is arranged between said third side and the exhaust hood. 
     
     
       13. The method of  claim 9 , wherein a variable speed supply fan is coupled to the controller and operable to deliver air to said area, and further comprising adjusting a speed of the supply fan using the controller responsively to the speed of the exhaust fan. 
     
     
       14. The method of  claim 9 , wherein said sensor support includes a tensioned cable, and further comprising repositioning the spillage sensor by sliding the sensor along the tensioned cable. 
     
     
       15. The method of  claim 9 , wherein the spillage probe assembly further includes a second spillage sensor, and said sensor support suspends both of the spillage sensors from the open housing such that each spillage sensor can be slidably repositioned along the open housing independent of each other and such that each spillage sensor is isolated from the open housing. 
     
     
       16. The method of  claim 9 , wherein the spillage probe assembly includes an over-ride unit coupled to the controller and configured to provide manual control of the speed of the exhaust fan.